Operating device for a sound recording and reproducing apparatus



Sept. 30, 1958 G. STEINEGGER 2,853,888

OPERATING DEVICE FOR A SOUND RECORDING AND REPRODUCING APPARATUS Filed Feb. 27. 1956 I NVENTOR: Cmovunui hma ger B3 MUAMQ $+M m United States Patent D l OPERATING DEVICE FOR A SOUND RECORDING AND REPRODUCING APPARATUS Giovanni Steinegger, Aurigeno, Tessin, Switzerland Application February 27, 1956, Serial No. 568,099

Claims priority, application Switzerland October 10, 1955 Claims. (Cl. 74-472) spatially superposed driving discs for winding up or for unspooling the steel tape and in which switching in and oil? of the motor current is eifected by a step-by-step switch.

The invention aims at the provision of such a device in which the means effecting the tilting movement of the motor is coupled with the device actuating said step-bystep switch in such a way that as the motor current is switched-in the driving wheel of the motor is brought into contact with the driving disc to be driven.

The invention further aims at the provision of a rod for operating the step-by-step switch, which rod in its rest position is kept spaced apart from the switch by a spring so that the rod may engage the switch only after having overcome the action of said spring and that subsequent to its liberation said rod is brought back into its original position by said spring.

This rod may be provided with a device owing to which the switching movement of the rod also determines the angular position of the motor shaft. For this purpose the rod carries a fork receiving a crank having a shaft effecting an angular rotation when the position of the crank is varied by a prong of the fork, thereby actuating a device adjusting the angular position of the motor shaft. The last-mentioned device consists of the rigid connection of the motor housing with an arm of a toggle joint the position of which, resulting from the action of the crank shaft, either on this or on the other side of the dead center position, gives the motor an inclination in which the driving wheel of the motor contacts either the driving disc for the winding on or the driving disc for the unspooling of the steel tape, respectively. Thereby the passage through the dead center position, upon change of the direction of the spooling, may advantageously be accelerated by a snap spring imparting to the motor driving wheel the pressure necessary for driving the driving disc.

Preferably the device is such that at the transition to the standstill the current is disconnected slightly subsequent to the separation of the driving wheel of the motor from the driven disc. Thereby an improved braking is obtained and rupture of the steel tape is prevented.

Other features and advantages of the invention will become apparent from the description now to follow of a preferred embodiment thereof, in which reference will be made to the accompanying drawing showing a circuit diagram of a sound recording and reproducing apparatus.

In this drawing reference numeral 1 designates an electromotor tiltable about an axle 4 extending vertically to the motor shaft. From the superposed driving discs for the bobbins adapted to receive the steel tape only the lower ones is visible on the drawing and designated by 5.

Patented Sept. so,

These driving discs are driven by a driving wheel 3 of the motor and depending on the driving of the lower or of the upper disc by the driving wheel of the motor, the bobbins for the steel tape are rotated in a clockwise or in a counterclockwise direction. The change from the winding on to the unspooling is obtained by tilting the motor about axle 4, whereby the shaft 2 takes the corresponding angular position. For changing the angular positionof the motor there is provided .an actuating rod 8 carrying a fork having prongs 11. Arranged between these prongs there is a crank 12 resting on the rod 8. By sliding the latter upwardly or downwardly an angular movement of the crank is obtained which is transmitted by the crank shaft to 'a leg 13 connected therewith. A toggle joint is further provided and rigidly connected by its one lever 15 with the motor. The other lever of this toggle joint is constituted by a snap spring 14 the end of which is stretched over the leg 13 in such a way that the angular rotation of crank 12 is transmitted to spring 14 which owing to the spring load resulting forces the toggle joint at great velocity over the dead center position into the opposite end position. As lever 15 is rigidly connected with the motor, the latter takes the corresponding angular position so that its driving wheel is in driving contact with the driving disc to be driven in this position.

-By pressing the knob 9 the actuating rod 8 is pressed downwardly and engages with its end the switch 16 constructed as a step-by-step switch. The current is switched on or ofi by a collector 17. In its rest position the rod 8 is kept spaced from switch 16 by the spring 10 so that it may only cut off the switch after having overcome the force of spring 10 and so that after its liberation it returns into its rest position under the action of said spring. Subsequent to its passage through the collector 17 the current is fed to the motor over conduits 18, 19 and 20.

Operation of the actuating knob 9 thus starts two functions: First the motor receives the spring loaded inclination necessary for driving and, second the step-by step is actuated and the motor is energized.

In order to vary the angular position of the motor use is made of the actuating rod 21. By pressing downwardly the knob 22 the rod 21 is guided downwardly and over a lever system 23 comprising a tiltable lever pivoted at 24 the rod 8 is guided upwardly to such an extent that the angular abutment of the crank 12 changes into the other direction. It results therefrom that also the toggle joint deflects to the other direction and imparts to the motor shaft 2 the corresponding inclination. If the driving wheel of the motor previously was in contact with the lower driving disc it will now be guided upwardly and pressed against the upper driving disc and the winding direction is reversed.

The parts serving to actuate, start and stop the device are matched in such a way that at the transition to the standstill the disconnection of the current, i. e. the engagement of the rod into the switch in order to open the latter, is eifected slightly later than the disconnection of the driving wheel of the motor from the driven disc obtained by the fork producing the corresponding tilting movement.

Other parts of the device which are not in immediate connection with actuating device of the present invention are not represented in the drawing the steel tape 6 and the recording head 7 excepted.

I claim:

1. In an operating device for a sound recording and reproducing apparatus having a motor tiltable about an axle extending vertically to the motor shaft and carrying a driving wheel afiording driving contact of the latter with one of two superposed driving discs for winding up or for unspooling the tape, in combination, a switch con- 'nected in circuit with the motor for controlling operationzthereof, .a tilting device :for tilting the motor, an actuating device for actuating said switch, and means for coupling said actuating device with said tilting device in such :a manner :that ,upon energizing of the motor, the driving 'wheel .of the latter is brought into contact with a driving disc p to be .driven, said means including a rod movable between rest andanoperative positions for actuating said switch and a spring acting .upon said rod for maintaining the latter spaced apart from said switch in its rest position so :that engagement of said switch by said rod is possible only after the latter has overcome the spring force and that after its liberation 'Ihfi rod returns into its rest position under :the action of said spring.

2. 1n a device as claimed .in claim 1,, the provision of a fork on said rodand of a crank located "between the prongs of said fork so that displacement .of 't-the fork 1esults in :an angular rotation of the crank shaft :by one prong of the fork, :and of means for actuating by this rotation of the crank shaft a device determining ithe an- :gular position of the motor shaft.

3. A device :as claimed in claim 2, comprisingaa toggle joint connected with the housing of the :motor and roperated by the crank shaft imparting .to it "a position .on either side of the dead .center position whichrinclines ;the motor to such an extent, that the driving wheelmf the latter contactseither one of thendrivingxiiscs :foruwinding on or unspooling the tape.

4. A device as claimed in claim 3, comprising 2a snap spring for accelerating the passage through the --;dead

center position and affording the operating pressure necessary forithe driving cooperation between the motor .wheel and driven driving disc.

5. A motor control arrangement comprising, in combination, a support; an electric motor mounted on said support for movement relative thereto between two operative positions; switch ,means connected in circuit with said motor for controlling operation thereof; and control means for moving said motor between its two .positions and for actuating said switch means, said control means having two control members each ,of which is adapted to be actuated by an operator, said control meansibeing so constructed and arranged that upon actuation and release of .one of said control members said References Cited in the file-of this patent UNITED STATES PATENTS 1,363,991 Monnot Dec. 28, "1920 2,927,844 Skolfield Jan. 14, 1936 2,468,453 'Mallentjer Apr. 26, 1949 Barbara et a1. July 15, 1952 

